Luke Skinner

Dr Luke Skinner

Research Fellow

Organisation

University of Cambridge

Research summary

My research looks at the role of ocean circulation in past climate change, including in particular its impacts on the carbon cycle and the transport of heat across the globe. One aspect of this work involves the reconstruction of how the radiocarbon activity of the deep-sea (i.e. its ‘age’ relative to the contemporary atmosphere) has changed over time. This is done by determining the radiocarbon age offset between coexisting planktonic (surface-dwelling) and benthic (bottom- dwelling) calcareous microfossils that have been selected from marine sediment sequences. An estimate of deep-sea ‘ventilation’, or the amount of time that carbon dioxide (CO2) dissolved in the deep-sea has been sequestered from the atmosphere, is thus obtained. Because the ocean is a vast and dynamic carbon reservoir containing roughly 60 times more carbon than the atmosphere, small changes in carbon retention by the deep-sea have the potential to cause significant changes in atmospheric CO2. One of my goals is to use radiocarbon ‘ventilation’ records to understand how changes in deep-sea carbon sequestration may have triggered the fluctuations in atmospheric CO2 that contributed to global de-glaciations in the past. Ultimately, this work aims to provide a ‘geological’ basis for understanding the complex interplay between the carbon cycle and ocean – atmosphere dynamics in the modern climate system.